1. Field of the Invention
The present invention relates to safety valves and, more particularly, to safety valves for use with a firehose.
2. Description of Related Art
Firehoses, whether in fluid communication with a pump in a fire truck, a fire hydrant or other source of water under high pressure, emit a high flow rate of water at significant pressure. The reactionary forces present at the nozzle of a firehose are sufficient to require a strong fireman to hold and aim the nozzle. In some situations, two or more firemen are required for safety reasons as well as to aim the emitted stream of water at a location of interest. In the event the firemen lose control of the nozzle due to injury, tripping and falling or other cause, the nozzle will thrash about and becomes a life threatening object to any persons in the vicinity. Additionally, significant damage to adjacent structures, the nozzle and the firehose may occur.
Conventional firehoses include a well known lever operated ball valve to shut off the flow of water. However, if the fireman handling the nozzle loses control due to tripping, injury or other event, it may not be possible to close the ball valve. The resulting loose firehose becomes a danger to life and property.
When a fire gets out of hand and may threaten a fireman, the firehose itself is sometimes used to guide a fireman out of a smoke filled room or out of another location where vision is impaired. If the nozzle is no longer under control and the firehose thrashes about, it can no longer serve as a guide to permit a fireman to escape to safety.
The present invention is directed to a safety valve for reducing, but not terminating, a high rate of flow under high pressure from the nozzle of a firehose. A manually gripable handle of the safety valve must be manually repositioned to and manually maintained in a fully open state to maintain open the passageway for water flowing through a firehose to the water emitting nozzle. Upon release of the handle due to accident or otherwise, the flow rate through the safety valve is automatically severely curtailed, but not terminated, to preclude occurrence of water hammer and possible damage to ancillary equipment; also the loose firehose nozzle is prevented from thrashing about and potentially causing injury or damage to property. Such reduction of flow rate results from the water flow within the valve acting upon a vane to reposition the vane to automatically restrict further water flow. Thereby, the water flow itself actuates the valve to place it in its nearly closed position and no ancillary power source is required.
The primary object of the present invention is to provide a safety valve for use with conventional firehoses.
Another object of the present invention is to provide a safety valve located intermediate a conventional ball valve and a nozzle of a firehose.
Yet another object of the present invention is to provide a safety valve which nearly closes upon release of a handle.
Still another object of the present invention is to provide a safety valve energized by the flow of fluid upon release of a handle to nearly terminate further fluid flow.
A further object of the present invention is to provide a self energized safety valve for nearly curtailing a flow of fluid upon release of a retaining element.
A yet further object of the present invention is to provide a safety valve that may be retrofitted to existing firehoses.
A still further object of the present invention is to provide a safety valve which will not give rise to water hammer and subsequent damage to pumps and other equipment.
A still further object of the present invention is to provide a method for nearly curtailing the flow of water through the nozzle of a firehose upon release of the discharge end of the firehose.
These and other objects of the present invention will become apparent to those skilled in the art as the description proceeds.